How CT Scanning Uncovers Part Flaws

CT Scanning – A Manufacturer’s Best Friend

Computed Tomography, or CT Scanning for short, allows Engineering Services & Metrology firms like Nel Pretech to be able to access the inner details of products or parts without the need to disassemble or destroy said part. So, manufacturers, why is this important to you? Well, there are several reasons, but one significant one is that when you create the first prototype, we can measure all features on a part, including internal parts, without harming that part to identify part flaws. Not only does the original part stays intact, but we can tell you exactly where you may need to make modifications to improve the part and reduce its costs.

In our previous CT article, we discussed assembly defect and provided a real-world example on how CT Scanning is used to identify part defects when trying to assemble two parts together.

Using the datum structures of each part, Nel Pretech was able to digitally overlay the data onto the CAD model generating a color map and pass the measurements back to the manufacturing company to help them develop their new parts. In today’s article, we are going to discuss Part Flaws and how those can be identified using CT Scanning.

How do I know if my parts have flaws?

There is nothing more exciting than taking your brand new part off of the assembly line as the first prototype. You are ready to test and bring this part to market immediately. One of the best ways to identify flaws is to have it measured via CT Scanning.

CT data is going to be compared against the CAD model to generate a color map (a heat map of the vector deviations of the actual part to the nominal CAD object) to make sure the part does not have any significant flaws well before you even think about bringing this to market.

Part Flaws Identification

We are going to use an example of a plastic injection molding part that we had previously scanned for a successful project. When engage in part flaw analysis, one of the common deliverables for analysis is a color map. To create this color map, our engineers use the print datums to precisely align the part to the CAD model, which is seen in the picture. The white object is the 3D reconstruction of the CT data and the tan color is the CAD model. The CT data has been overlaid onto the CAD object allowing the user to get a feel for what the actual part looks like relative to the ideal part.

Once our engineers overlay the CT data onto the CAD model, they can map all the vector deviations between the part and the CAD model, displaying those to the client digitally in the color map. Our engineers then determine a scale (depending on the tolerances) for the color map to show all of the vector deviations in a quantifiable manner. For example, this picture is showing a scale of +/- 1 millimeter of vector deviation.

What is the takeaway?

You should now start to see that CT Scanning is an incredibly powerful tool that gives you the ability to take a CT scan, map the deviations of the actual part relative to the CAD object, and determine the flaws of your parts. What is really cool about the color map deliverable that we provide you with is that you have the ability to drop an indicator anywhere on the color map and it will tell you exactly how much your part is deviating from the CAD model at that discrete location. Using CT Scanning to perfect your parts is going to save you time in testing and thousands of dollars in part development.